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How to Use Glycolic Acid and Niacinamide in Your Skincare Routine for Smooth, Bright, Even-Toned Skin

A dynamic duo to get you glowing.
Glycolic acid and niacinamide

Glycolic acid and niacinamide are two of the most popular active ingredients in skincare products right now. And it’s no wonder, since they promise to make your skin look smoother, brighter and more even (among many other benefits). So why not incorporate both of them into your routine?

But that’s where things can get tricky. Should you mix them together, or look for both in one product? Is it better to apply them in layers? Which one goes on first? And will one inactivate the other?

If you’ve been pondering these questions, this tutorial is for you. Keep reading to learn what glycolic acid and niacinamide can do for your skin, why they’re better together, how to use both in one routine, and the best products to try.

What Does Glycolic Acid Do for Your Skin?

  • Exfoliates dead skin: It breaks down the “glue” that holds dead skin cells together in the stratum corneum (the uppermost layer of our skin). This allows them to be sloughed off, revealing the fresh new skin underneath.[1]
  • Smooths texture: A study found that as little as 5% produced a significant improvement in general skin texture after three months.[2]
  • Brightens and fades pigmentation: All hydroxy acids help with brightening by removing the old dead skin cells that contribute to dull-looking skin. Glycolic acid has also been shown to improve sun-induced discolourations and sallowness[2][3].
  • Thickens and firms: By increasing collagen production,[4] glycolic acid can help skin to feel thicker and firmer. One study, using a 15% concentration, found that it increased epidermal thickness by 27% after six months.[5]
  • Improves hydration: As a humectant, glycolic acid draws moisture into the skin. It also increases the skin’s hyaluronic acid content.[6]

What Does Niacinamide Do for Your Skin?

  • Brightens and fades pigmentation: In addition to treating melasma,[7] it has been shown to significantly decrease hyperpigmentation.[8] One study found that, in combination with vitamins E and B5, it significantly improved skin tone evenness in only six weeks.[9]
  • Strengthens the skin barrier: It improves the function of the skin barrier by reducing TEWL (transepidermal water loss)[10] and increasing levels of ceramides and other barrier components.[11] This leads to a thicker, more resilient stratum corneum[12] that retains hydration[13] and is resistant to damage[10].
  • Reduces wrinkles: Multiple studies demonstrated that niacinamide helps with fine lines and wrinkles. For example, a concentration of 5% significantly reduced wrinkles after 12 weeks,[14] while 4% improved eye-area wrinkles in just eight weeks.[15]
  • Smooths texture: Both 4% and 5% also produce significant improvements in skin texture.[9][14]
  • Reduces oil and clears acne: It can help to control excess oil by lowering the amount and rate of sebum excreted.[16] For mild to moderate acne, two studies have found niacinamide to be comparable in efficacy to clindamycin, a topical antibiotic.[17][18]
  • Calms redness: Last but not least, it can also help with red, blotchy skin[14] and even rosacea.[19]

Should You Use Both Glycolic Acid and Niacinamide?

This is because glycolic acid is notoriously irritating, thanks to its low molecular weight. For many people, it can cause dry, flaky skin and even redness, stinging and inflammation, especially when first starting treatment. This is expected and usually improves as your skin gets used to the acid. However, it’s also important to choose an appropriate strength of glycolic acid, and use it only as often as your skin can tolerate.

Niacinamide can help to minimize these potential side effects by making your skin barrier stronger and thicker. It won’t be as vulnerable to irritation, and will become better at holding onto moisture. It will also help to calm down any redness.

Best of all, by using these two ingredients, you’ll be getting double the benefits in terms of smoothing, brightening, fading pigmentation, firming and reducing wrinkles. What’s not to love about that?!

Can You Mix Glycolic Acid and Niacinamide?

Your Acid Won’t Be Effective

Combining these ingredients is going to make your acid less effective. In order to do their jobs, hydroxy acids are formulated at a certain pH level. For glycolic acid, it’s typically between pH 3.0 and 4.0.

But niacinamide has a much higher pH, around 6.0. So if you mix the two ingredients together, the niacinamide is going to raise the pH of the glycolic acid, so it will no longer be acidic.

That means you won’t get much (if any) benefit from using the acid. One study compared the absorption of AHAs at pH 3.0 and 7.0, and found that the higher the pH, the less the skin absorbs—and the less activity the AHAs have on the skin.[20]

You Can Trigger a “Niacin Flush”

Another problem with mixing glycolic acid and niacinamide is that it can cause redness and flushing. This is from the glycolic acid lowering the pH of the niacinamide below its optimal range.

While niacinamide is meant to be around pH 6.0, acidic conditions can trigger its conversion into niacin, another form of vitamin B3.[21]

If you’ve ever taken an oral niacin supplement, then you may have experienced the infamous “niacin flush.” Although harmless, it temporarily makes your skin red, hot and flushed (due to the release of prostaglandin D2).[22]

Now, imagine the same thing, but concentrated on your face. I’ve tested this out myself, and it's no joke. I looked like a lobster, felt very uncomfortable, and the effect lasted one to two hours. Makeup can’t even cover it up! 

I believe this is why some people think they can’t tolerate niacinamide, even though it is one of the gentlest and most non-toxic ingredients in skincare. If you’re incorrectly combining it with an acid, it can appear to cause irritation, even though it’s just this “niacin flush.”

How to Use Glycolic Acid and Niacinamide Together

1. Apply Them in a Single Product

While it’s not advisable to play chemist and mix two separate products, you can use a pre-made product that includes both glycolic acid and niacinamide together. This is because it will be expertly formulated to remain stable and effective at a certain pH level. 

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